The invention relates to a semiconductor device.
Recently, the concept of soldering semiconductor substrates directly onto a mounting platform such as e.g., a printed circuit board (PCB) has become popular because of its potential to reduce cost and size of the device. A major challenge in the related art is the need of stress compensation between the semiconductor substrate and the mounting platform. Typically, the semiconductor substrate and the mounting platform have different thermal expansion properties which cause the development of stress at the connections (typically solder bumps) between these two parts. As a result, especially in the case of larger semiconductor substrates, warpage may occur and can be the cause of solder bump cracks or other fatal defects.
A number of counter measures are known. In some cases, a mounting platform having a thermal expansion which better matches to the thermal expansion of the semiconductor substrate may be used. Further, an underfill material may be applied between the semiconductor substrate and the mounting platform and acts as a stress absorbing interlayer. Another possibility is to counter the occurrence of shear forces by the use of solder bumps having improved resilience or crack resistance.
For these and other reasons, there is a need for the present invention.